Beastmaster of the Ages - Chapter 7 - Mysterious Black Arm!

The main character Lei Yu does not have the ability to practice his family’s martial arts. He gets stepped on and tossed around. Due to certain reasons, he leaves the family, coincidentally gains an ability, and makes his own path to becoming an immortal.

I, an ordinary high school student, Kimizuka Kimihiko, who easily gets involved in things, was appointed to take care of mysterious attache cases by mysterious men in black suits. After meeting a beautiful angel-like detective girl, named Siesta in a hijacked plane, I became her assistant.

And from there–

[You deal with the beehive, and I’ll restrain the enemy.] [Don’t make plans that make me the victim.]

We had those kinds of foolish conversations, all while being completely broke every day and fought against . Even when there were hurricanes, the weather-beaten duo sleep past it. Sometimes when we saved money at a casino, we would jump around on the beds at a resort hotel, only to be broke again the next day. We would walk through deserts, traverse through jungles, conquer mountains, cross oceans– The great detective and her assistant would go through these dazzling adventures–

Until she died.

And this story starts from 1 year after that incident.

I’m the only one who’s left, but I carry on her remained wishes.

This story is far from over..

[Congratulations! You’ve unlocked the Dimensional Motel System.][First Mission: A runaway princess—hailed as the most beautiful in the land is being hunted by her step-mother. She was originally headed to the dwarves’ cottage, but the System has rerouted her to your motel instead.][Protect her. Win her trust. And if you manage to woe her, you’ll earn her Affection Points.][Bonus Mission: Sleep with her evil stepmother to unlock more reward]'What kind of weird mission is this? And why does this story sound way too familiar?'